Surely if a substantial, eg foundations, start has been made then the planning won't lapse.
If you read the various threads by this person they have had some issues with their builder and seem to be in a genuine fear that some kind of planning and building control "police" will be coming round to take them away. They may want to reinstate the project in future or sell the house with planning approval so it's probably in their interests for the work to have "commenced". Certainly no need to "eradicate" it from the face of the earth.